Health and Nutrition Stuff

03 Apr2013

Paleomythic: How people really lived during the Stone Age

A growing movement seeks to reproduce the hunter-gatherer lifestyle: running barefoot, pondering polygamy, relying on a diet of meat. But even our ancestors never lived this way. And besides, modern humans have evolved.

The Paleo diet is just the beginning. It’s the gateway to an entire suite of lifestyle prescriptions devoted to mimicking the way our ancestors ate, moved, slept, and bred nearly 10,000 years ago in the Paleolithic era of hunting and gathering, an era Paleo followers associate with strong bodies and minds.

Members of this modern-day caveman community believe the path to optimal health is through eating only what our ancestors ate before modern agriculture and a shift to more sedentary ways. Devoted proponents of a Paleo lifestyle not only subsist primarily on meat and eschew carbs; they also exercise in short bursts of activity intended to mimic escaping prey. Even blood donation has become a Paleo fad among the most dogmatic of 21st-century cavemen, based on the notion that our ancestors were often wounded, making blood loss a way of life.

But new research reveals flaws in the logic behind these trends. As evolutionary and genetic science show, humans, like all other living beings, have always been a work in progress and never completely in sync with the natural world. If we’re going to romanticize and emulate a particular point in our evolutionary history, why not go all the way back to when our ape ancestors spent their days swinging from tree to tree?

It is hard to argue that a simpler life with more exercise, fewer processed foods, and closer contact with our children may well be good for us, but rather than renouncing modern living for the sake of our Stone Age genes, we need to understand how evolution has—and hasn’t—suited us for the world we inhabit now.

Modern mimic: The first formalised suggestion that we should be relying on meat and modeling ourselves, at least food-wise, after our cave-dwelling ancestors came from The Stone Age Diet, a 1975 book by gastroenterologist Walter Voegtlin. Its more recent successors include The Paleo Diet, The Primal Diet, and The Paleo Solution: The Original Human Diet.

These diets differ in their details but share an emphasis on meat and strictures against virtually all carbohydrates, sweets, and processed foods. The problem, claim Paleo followers, is that humans have not, in the past 10,000 years, adapted enough to safely consume grains.

Science weighs in: Bold declarations that our ancestors exclusively consumed meat turn out to be untrue. Studies of fossil hominins suggest that their sturdy premolar teeth may have been used either to open seeds or chew starchy underground tubers and bulbs. In late 2010, scientists detected bits of plants, including cattail-like roots, on the grinding stones from 30,000-year-old archaeological sites in Italy, Russia, and the Czech Republic. They concluded that our ancestors were mixing the ground-up plants with water to make a pita bread of sorts.

Katherine Milton is an anthropologist at the University of California, Berkeley who has studied and written extensively about the diets of hunter-gatherers and ancient humans. She points out that “it is difficult to comment on ‘the best diet’ for modern humans because there have been and are so many different yet successful diets in our species.”

Furthermore, “because some hunter-gatherer societies obtained most of their dietary energy from wild animal fat and protein does not imply that this is the ideal diet for modern humans, nor does it imply that modern humans have genetic adaptations to such diets.”

The notion that humans got to a point in evolutionary history when their bodies were somehow “in sync” with the environment, and that at some time after that point—whether due to the advent of agriculture, the invention of the bow and arrow, or the availability of the hamburger—we went astray from those roots reflects a misunderstanding of evolution.

What we are able to eat and thrive upon depends on our 30 million years plus of history as primates, not a single arbitrarily more recent moment in time.....